CVE-2026-28387
Description
A flaw was found in OpenSSL. An uncommon configuration of clients performing DANE TLSA-based server authentication, when paired with uncommon server DANE TLSA records, may result in a use-after-free and/or double-free on the client side. This vulnerability could lead to data corruption, application crashes, or, in severe cases, arbitrary code execution. This issue is highly specific and uncommon, as it only affects clients using both PKIX-TA(0)/PKIX-EE(1) and DANE-TA(2) certificate usages and communicating with a server publishing a TLSA record set with both types of records.
Statement
This Low impact vulnerability affects clients performing DANE TLSA-based server authentication only when configured with an uncommon combination of PKIX-TA(0/PKIX-EE(1) and DANE-TA(2) certificate usages. Most common SMTP MTA deployments are not vulnerable as they are recommended to treat PKIX certificate usages as unusable. Exploitation also requires communication with a server publishing a TLSA RRset with both types of records.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.7 | 8.1 | 8.1 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | High | High | High |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | High | High |
| Integrity Impact | None | High | High |
| Availability Impact | Low | High | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Availability,Integrity
Technical Impact: DoS: Crash, Exit, or Restart
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